Agroinfiltration Mediated Scalable Transient Gene Expression in Genome Edited Crop Plants

Agrobacterium-mediated transformation is one of the most commonly used genetic transformation method that involves transfer of foreign genes into target plants. Agroinfiltration, an Agrobacterium-based transient approach and the breakthrough discovery of CRISPR/Cas9 holds trending stature to perform targeted and efficient genome editing (GE). The predominant feature of agroinfiltration is the abolishment of Transfer-DNA (T-DNA) integration event to ensure fewer biosafety and regulatory issues besides showcasing the capability to perform transcription and translation efficiently, hence providing a large picture through pilot-scale experiment via transient approach. The direct delivery of recombinant agrobacteria through this approach carrying CRISPR/Cas cassette to knockout the expression of the target gene in the intercellular tissue spaces by physical or vacuum infiltration can simplify the targeted site modification. This review aims to provide information on Agrobacterium-mediated transformation and implementation of agroinfiltration with GE to widen the horizon of targeted genome editing before a stable genome editing approach. This will ease the screening of numerous functions of genes in different plant species with wider applicability in future.

Optimization of Agrobacterium-mediated transformation conditions of prospective genotypes of winter bread wheat by in planta method

Aim. Optimization of conditions for genetic transformation of new promising genotypes of winter bread wheat (T. aestivum L.) by in planta method. Methods. Agrobacterium-mediated transformation by in planta method using the strain AGL0 and vector construct pBi2E. Results. The influence of air temperature, optical density of cells of agrobacterial suspension, inoculation day and composition of inoculation medium on the frequency of obtaining transgenic plants of new winter wheat genotypes was studied. The dependence of the frequency obtaining of transgenic plants from environmental conditions, in particular temperature, has been established. It was found that the temperature regime of 20-22°C provided the largest number (4.8%) of wheat transformants, and when the temperature is reduced to 16-18°C there is a decrease in the efficiency of T-DNA transfer into the plant genome and the lowest frequency of transformation (0.7%). Conclusions. The largest number of transformants was obtained using a inoculation medium without sucrose, the optical density of cells of the agrobacterial suspension of 0.6 op.od. and inoculation on the third day after castration of ears. Keywords: T. aestivum, Agrobacterium-mediated transformation in planta, optimization of conditions.

Genetic transformation of promising genotypes of winter bread wheat by in planta method

Aim. Optimization of conditions and genetic transformation of new promising genotypes of winter bread wheat (Triticum aestivum L.) by in planta method. Methods. Agrobacterium-mediated transformation by the in planta method using strain AGL0 and vector construct pBi-OAT. Results. The influence of air temperature, optical density of cells of agrobacterial suspension, inoculation day and composition of inoculation medium on the frequency of obtaining transgenic plants of new promising genotypes of winter wheat was studied. The dependence of the frequency of obtaining transgenic plants on environmental conditions, in particular temperature, has been established. It was found that the temperature regime of 20-22 °C provided the largest number (4.4%) of wheat transformants, and when the temperature is reduced to 16-18 °C there is a decrease in the efficiency of T-DNA transfer into the plant genome and the lowest frequency of transformation is observed. Conclusions. The largest number of transformants was obtained using a inoculation medium without sucrose, the optical density of cells of the agrobacterial suspension of 0.4 op.od. and inoculation on the third day after castration of ears. Keywords: Triticum aestivum L., Agrobacterium-mediated transformation, ornithine-δ-aminotransferase gene.